package bitetorrent.helper;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 *
 * @author vaio
 */
public class Digest {

    private static String convertToHex(byte[] data) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < data.length; i++) {
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                if ((0 <= halfbyte) && (halfbyte <= 9)) {
                    sb.append((char) ('0' + halfbyte));
                } else {
                    sb.append((char) ('a' + (halfbyte - 10)));
                }
                halfbyte = data[i] & 0x0F;
            } while (two_halfs++ < 1);
        }
        return sb.toString();
    }

    public static String SHA1(String text)
            throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA-1");
        byte[] sha1hash = new byte[20];
        byte[] bytes = text.getBytes();
        md.update(bytes, 0, text.length());
        sha1hash = md.digest();
        
        return convertToHex(sha1hash);
    }
    
    public static byte[] SHA1InByte(String text) throws NoSuchAlgorithmException {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA-1");
        byte[] sha1hash = new byte[20];
        byte[] bytes = text.getBytes();
        md.update(bytes, 0, text.length());
        sha1hash = md.digest();

        return sha1hash;
    }

}
